Vibration motor and mobile terminal having the same

ABSTRACT

A vibration motor includes a housing, a coil, a moving portion, an elastic member and a roller member. The housing has a top surface, a bottom surface, and first to fourth side surfaces joining the top surface to the bottom surface, the first to fourth surfaces defining an inner circumferential surface of the housing. The coil is provided in the housing. The moving portion provided in the housing and the moving portion is configured to reciprocate between the first and third sides arranged opposite to each other. The elastic member is provided between the moving portion and the housing. The roller member is provided in the housing and arranged to come into rolling contact with the top or bottom surface of the housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. §119(a), this application claims the benefit ofearlier filing date and right of priority to Korean Application No.10-2012-0012516, filed on Feb. 7, 2012 and Korean Application No.10-2012-0023541, filed on Mar. 7, 2012 the contents of which areincorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a vibration motor formed to vibrate aterminal and a mobile terminal having the vibration motor.

2. Description of the Conventional Art

As functions of a terminal are varied, the terminal is implemented as atype of a multimedia player having complex functions, for example, afunction of photographing photos or moving pictures, a function ofreproducing music and moving picture files, a function of playing games,a function of receiving broadcasting, etc.

Terminals may be divided into a mobile/portable terminal and astationary terminal depending on their mobility. The mobile terminal isa portable device that can be carried anywhere and have one or more of afunction of performing voice and video calls, a function ofinputting/outputting information, a function of storing data, etc.

Efforts for improving the structural and/or software part of the mobileterminal have been made in order to support and develop these functionsof the mobile terminal.

A vibration motor is a component that converts electrical energy intomechanical vibration using a principle of generating electromagneticforces. The vibration motor has gradually become small in size and lightin weight. The vibration motor is mounted in a portable terminal so asto provide a mute incoming-call notice function or various vibrationfunctions.

Particularly, as the portable terminal has a small size and highquality, a liquid crystal display (LCD) such as a touch screen type LCDis employed in the portable terminal. As there are required functionssuch as a function of generating vibrations when a touch screen istouched, the improvement of the vibration motor has become moreimportant.

A linear vibration motor can be considered as an example of theimprovement. The linear vibration motor does not use a principle ofrotating a motor, but generates vibrations by electromagnetic forcehaving a resonance frequency determined by using a spring installedtherein and a mass body coupled with the spring.

Therefore, it is required to consider a plan for allowing a vibrationmotor to become slimmer or allowing the vibration motor to be moreefficiently operated by improving components used.

BRIEF SUMMARY OF THE INVENTION

Therefore, an aspect of the detailed description is to provide avibration motor which has a further improved structure and allows amobile terminal to become slimmer.

To achieve these and other advantages and in accordance with the purposeof this specification, as embodied and broadly described herein, avibration motor includes a housing formed so that the innercircumferential surface except top and bottom surfaces of the housinghas first to fourth sides; a coil formed in the housing; a movingportion formed to reciprocate between the first and third sides oppositeto each other; an elastic member formed between the moving portion andthe housing; and a roller member formed to come in rolling contact withthe top or bottom surface of the housing.

In one exemplary embodiment, the roller member may be coupled to thehousing.

In one exemplary embodiment, the roller member may be coupled to themoving portion.

In one exemplary embodiment, the elastic member may be formed betweenthe moving portion and the first side or between the moving portion andthe third side.

In one exemplary embodiment, the elastic member may be formed in pluralnumbers, and the elastic coefficient of the elastic members formed atany one side may be different from that of the elastic members formed atthe other side.

In one exemplary embodiment, the moving portion or the housing may haveinsertion grooves into which the respective elastic members areinserted.

In one exemplary embodiment, the moving portion may have a magnet and ayoke formed to determine the direction of an electromagnetic force ofthe magnet.

In one exemplary embodiment, the housing may have first and secondcovers coupled to each other, and the first or second cover may have amounting groove recessed from one surface thereof so that the coil ismounted in the mounting groove.

In one exemplary embodiment, the reciprocating direction of the movingportion may be an extending direction of the first and third sides.

To achieve these and other advantages and in accordance with the purposeof this specification, as embodied and broadly described herein, amobile terminal includes a terminal main body; and a vibration motorcoupled to the terminal main body so as to vibrate the terminal mainbody, wherein the vibration motor includes a housing having first andsecond covers coupled to each other so as to define an internal space; acoil formed in the housing; a moving portion formed to reciprocatebetween first and third sides opposite to each other in the internalspace according to a change in electromagnetic field induced by thecoil; and a roller member formed to come in rolling contact with thefirst or second cover of the housing.

To achieve these and other advantages and in accordance with the purposeof this specification, as embodied and broadly described herein, amobile terminal includes a terminal main body; and a vibration motorcoupled to the terminal main body so as to vibrate the terminal mainbody, wherein the vibration motor includes a housing having first andsecond covers coupled to each other so as to define an internal space; amoving portion fanned to reciprocate between first and third sidesopposite to each other in the internal space; an elastic member formedbetween the moving portion and the housing; and guide portionsrespectively formed at second and fourth sides adjacent to the first andthird sides so as to guide the moving portion.

The mobile terminal according to the exemplary embodiments configured asdescribed above uses a motor vibrated in the lateral direction, so thatit is possible to miniaturize the mobile terminal and to perform adesign for optimizing the deployment of components in the mobileterminal.

Further scope of applicability of the present application will becomemore apparent from the detailed description given hereinafter. However,it should be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention and wherein:

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a block configuration diagram of a mobile terminal accordingto an exemplary embodiment;

FIG. 2 is a front perspective view of a mobile terminal according to anexemplary embodiment;

FIG. 3 is a rear perspective view of the mobile terminal of FIG. 2;

FIG. 4 is a perspective view illustrating a state in which a batterycase is removed in FIG. 3;

FIG. 5 is a partial sectional view taken along line IV-IV of FIG. 4;

FIG. 6 is a perspective view of a vibration motor shown in FIG. 3according to a first exemplary embodiment;

FIG. 7 is an exploded perspective view of FIG. 6;

FIG. 8 is a sectional view taken along line V-V of FIG. 6;

FIG. 9 is a sectional view taken along line VI-VI of FIG. 6;

FIG. 10 is a sectional view of a vibration motor according to a secondexemplary view;

FIG. 11 is a perspective view of a moving body shown in FIG. 10;

FIG. 12 is a sectional view of a vibration motor according to a thirdexemplary view;

FIG. 13 is a perspective view of a second cover shown in FIG. 12;

FIG. 14 is a sectional view of a vibration motor according to a fourthexemplary view;

FIG. 15 is an exploded perspective view of FIG. 14;

FIG. 16 is a sectional view taken along line VII-VII of FIG. 14;

FIG. 17 is a sectional view taken along line VIII-VIII of FIG. 14; and

FIG. 18 is a sectional view taken along line IX-IX of FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, a vibration motor and a mobile terminal having the sameaccording to the present disclosure will be explained in more detailwith reference to the attached drawings. For the sake of briefdescription with reference to the drawings, the same or equivalentcomponents will be provided with the same reference numbers, anddescription thereof will not be repeated. Singular expressions includeplural expressions which do not have any obviously different meaning inview of a context.

The mobile terminal according to the present disclosure may include aportable phone, a smart phone, a laptop computer, a digital broadcastingterminal, Personal Digital Assistants (PDA), Portable Multimedia Player(PMP), a navigation system, etc. However, it will be obvious to thoseskilled in the art that the present invention may be also applicable toa fixed terminal such as a digital TV and a desktop computer.

The mobile terminal 100 includes a wireless communication unit 110, anA/V (Audio/Video) input unit 120, a user input unit 130, a sensing unit140, an output unit 150, a memory 160, an interface unit 170, acontroller 180, and a power supply unit 190. FIG. 1 shows the mobileterminal 100 having various components, but it is understood thatimplementing all of the illustrated components is not a requirement. Themobile terminal 100 may be implemented by greater or fewer components.Hereinafter, each of the above components will be explained.

The wireless communication unit 110 typically includes one or morecomponents allowing radio communication between the mobile terminal 100and a wireless communication system or a network in which the mobileterminal is located. For example, the wireless communication unit 110may include at least one of a broadcast receiving module 111, a mobilecommunication module 112, a wireless Internet module 113, a short-rangecommunication module 114, and a location information module 115.

The broadcast receiving module 111 receives broadcast signals and/orbroadcast associated information from an external broadcast managementserver (or other network entity) via a broadcast channel. The broadcastchannel may include a satellite channel and/or a terrestrial channel.The broadcast management server may be a server that generates andtransmits a broadcast signal and/or broadcast associated information ora server that receives a previously generated broadcast signal and/orbroadcast associated information and transmits the same to a terminal.The broadcast associated information may refer to information associatedwith a broadcast channel, a broadcast program or a broadcast serviceprovider. The broadcast signal may include a TV broadcast signal, aradio broadcast signal, a data broadcast signal, and the like. Also, thebroadcast signal may further include a broadcast signal combined with aTV or radio broadcast signal. The broadcast associated information mayrefer to information associated with a broadcast channel, a broadcastprogram or a broadcast service provider. The broadcast associatedinformation may be provided via a mobile communication network. In thiscase, the broadcast associated information may be received by the mobilecommunication module 112. The broadcast signal may exist in variousforms. For example, it may exist in the form of an electronic programguide (EPG) of digital multimedia broadcasting (DMB), electronic serviceguide (ESG) of digital video broadcast-handheld (DVB-H), and the like.

The broadcast receiving module 111 may be configured to receive signalsbroadcast by using various types of broadcast systems. In particular,the broadcast receiving module 111 may receive a digital broadcast byusing a digital broadcast system such as multimediabroadcasting-terrestrial (DMB-T), digital multimediabroadcasting-satellite (DMB-S), digital video broadcast-handheld(DVB-H), the data broadcasting system known as media forward link only(MediaFLO®), integrated services digital broadcast-terrestrial (ISDB-T),etc. The broadcast receiving module 111 may be configured to be suitablefor every broadcast system that provides a broadcast signal as well asthe above-mentioned digital broadcast systems.

Broadcasting signals and/or broadcasting associated information receivedthrough the broadcast receiving module 111 may be stored in the memory160.

The mobile communication module 112 transmits/receives wireless signalsto/from at least one of network entities (e.g., base station, anexternal terminal, a server, etc.) on a mobile communication network.Here, the wireless signals may include audio call signal, video callsignal, or various formats of data according to transmission/receptionof text/multimedia messages.

The wireless internet module 113 supports wireless Internet access forthe mobile terminal. This module may be internally or externally coupledto the mobile terminal 100. Examples of such wireless Internet accessmay include Wireless LAN (WLAN) (Wi-Fi), Wireless Broadband (Wibro),World Interoperability for Microwave Access (Wimax), High Speed DownlinkPacket Access (HSDPA), and the like.

The short-range communication module 114 denotes a module forshort-range communications. Suitable technologies for implementing thismodule may include BLUETOOTH, Radio Frequency IDentification (RFID),Infrared Data Association (IrDA), Ultra-WideBand (UWB), ZigBee, and thelike.

The position information module 115 denotes a module for sensing orcalculating a position of a mobile terminal. An example of the positioninformation module 115 may include a Global Position System (GPS)module.

Referring to FIG. 1, the A/V input unit 120 is configured to receive anaudio or video signal. The A/V input unit 120 may include a camera 121,a microphone 122 or the like. The camera 121 processes image data ofstill pictures or video acquired by an image capture device in a videocapturing mode or an image capturing mode. The processed image framesmay be displayed on a display 151.

The image frames processed by the camera 121 may be stored in the memory160 or transmitted via the wireless communication unit 110. The camera121 may be provided in two or more according to the configuration of themobile terminal.

The microphone 122 may receive sounds (audible data) via a microphone ina phone call mode, a recording mode, a voice recognition mode, and thelike, and can process such sounds into audio data. The processed audio(voice) data may be converted for output into a format transmittable toa mobile communication base station via the mobile communication module112 in case of the phone call mode. The microphone 122 may implementvarious types of noise canceling (or suppression) algorithms to cancel(or suppress) noise or interference generated in the course of receivingand transmitting audio signals.

The user input unit 130 may generate key input data from commandsentered by a user to control various operations of the mobilecommunication terminal. The user input unit 130 may include a keypad, adome switch, a touch pad (e.g., a touch sensitive member that detectschanges in resistance, pressure, capacitance, etc. due to beingcontacted) a jog wheel, a jog switch, and the like.

The sensing unit 140 detects a current status (or state) of the mobileterminal 100 such as an opened or closed state of the mobile terminal100, a location of the mobile terminal 100, the presence or absence ofuser contact with the mobile terminal 100, the orientation of the mobileterminal 100, an acceleration or deceleration movement and direction ofthe mobile terminal 100, etc., and generates commands or signals forcontrolling the operation of the mobile terminal 100. For example, whenthe mobile terminal 100 is implemented as a slide type mobile phone, thesensing unit 140 may sense whether the slide phone is open or closed. Inaddition, the sensing unit 140 can detect whether or not the powersupply unit 190 supplies power or whether or not the interface unit 170is coupled with an external device. The sensing unit 140 may include aproximity sensor 141.

The output unit 150 is configured to provide outputs in a visual,audible, and/or tactile manner. The output unit 150 may include thedisplay 151, an audio output module 152, an alarm unit 153, a hapticmodule 154, and the like.

The display 151 may display information processed in the mobile terminal100. For example, when the mobile terminal 100 is in a phone call mode,the display 151 may display a User Interface (UI) or a Graphic UserInterface (GUI) associated with a call or other communication (such astext messaging, multimedia file downloading, etc.). When the mobileterminal 100 is in a video call mode or image capturing mode, thedisplay 151 may display a captured image and/or received image, a UI orGUI.

The display 151 may include at least one of a Liquid Crystal Display(LCD), a Thin Film Transistor-LCD (TFT-LCD), an Organic Light EmittingDiode (OLED) display, a flexible display, a three-dimensional (3D)display, or the like.

Some of these displays may be configured to be transparent so thatoutside may be seen therethrough, which may be referred to as atransparent display. A representative example of the transparent displaymay include a Transparent Organic Light Emitting Diode (TOLED), and thelike. The rear surface portion of the display 151 may also beimplemented to be optically transparent. Under this configuration, auser can view an object positioned at a rear side of a body through aregion occupied by the display 151 of the body.

The display 151 may be implemented in two or more in number according toa configured aspect of the mobile terminal 100. For instance, aplurality of displays may be arranged on one surface integrally orseparately, or may be arranged on different surfaces.

Here, if the display 151 and a touch sensitive sensor (referred to as atouch sensor) have a layered structure therebetween, the structure maybe referred to as a touch screen. The display 151 may be used as aninput device rather than an output device. The touch sensor may beimplemented as a touch film, a touch sheet, a touch pad, and the like.

The touch sensor may be configured to convert changes of a pressureapplied to a specific part of the display 151, or a capacitanceoccurring from a specific part of the display 151, into electric inputsignals. Also, the touch sensor may be configured to sense not only atouched position and a touched area, but also a touch pressure.

When touch inputs are sensed by the touch sensors, corresponding signalsare transmitted to a touch controller (not shown). The touch controllerprocesses the received signals, and then transmits corresponding data tothe controller 180. Accordingly, the controller 180 may sense whichregion of the display 151 has been touched.

Referring to FIG. 1, a proximity sensor 141 may be arranged at an innerregion of the mobile terminal blocked by the touch screen, or near thetouch screen. The proximity sensor 141 indicates a sensor to sensepresence or absence of an object approaching to a surface to be sensed,or an object disposed near a surface to be sensed, by using anelectromagnetic field or infrared rays without a mechanical contact. Theproximity sensor 141 has a longer lifespan and a more enhanced utilitythan a contact sensor.

The proximity sensor 141 may include a transmissive type photoelectricsensor, a direct reflective type photoelectric sensor, a mirrorreflective type photoelectric sensor, a high-frequency oscillationproximity sensor, a capacitance type proximity sensor, a magnetic typeproximity sensor, an infrared rays proximity sensor, and so on. When thetouch screen is implemented as a capacitance type, proximity of apointer to the touch screen is sensed by changes of an electromagneticfield. In this case, the touch screen (touch sensor) may be categorizedinto a proximity sensor.

Hereinafter, for the sake of brief explanation, a status that thepointer is positioned to be proximate onto the touch screen withoutcontact will be referred to as ‘proximity touch’, whereas a status thatthe pointer substantially comes in contact with the touch screen will bereferred to as ‘contact touch’. For the position corresponding to theproximity touch of the pointer on the touch screen, such positioncorresponds to a position where the pointer faces perpendicular to thetouch screen upon the proximity touch of the pointer.

The proximity sensor 141 senses proximity touch, and proximity touchpatterns (e.g., distance, direction, speed, time, position, movingstatus, etc.). Information relating to the sensed proximity touch andthe sensed proximity touch patterns may be output onto the touch screen.

The audio output module 152 may convert and output as sound audio datareceived from the wireless communication unit 110 or stored in thememory 160 in a call signal reception mode, a call mode, a record mode,a voice recognition mode, a broadcast reception mode, and the like.Also, the audio output module 152 may provide audible outputs related toa particular function performed by the mobile terminal 100 (e.g., a callsignal reception sound, a message reception sound, etc.). The audiooutput module 152 may include a speaker, a buzzer, and so on.

The alarm unit 153 may provide outputs to inform about the occurrence ofan event of the mobile terminal 100. Typical events may include callreception, message reception, key signal inputs, a touch input, etc. Inaddition to audio or video outputs, the alarm unit 153 may provideoutputs in a different manner to inform about the occurrence of anevent. The video signal or the audio signal may be output via thedisplay 151 or the audio output module 152. Accordingly, the display 151or the audio output module 152 may be classified as part of the alarmunit 153.

The haptic module 154 generates various tactile effects which a user canfeel. A representative example of the tactile effects generated by thehaptic module 154 includes vibration. Vibration generated by the hapticmodule 154 may have a controllable intensity, a controllable pattern,and so on. For instance, different vibration may be output in asynthesized manner or in a sequential manner. The haptic module 154 maygenerate various tactile effects, including not only vibration, but alsoarrangement of pins vertically moving with respect to a skin beingtouched (contacted), air injection force or air suction force through aninjection hole or a suction hole, touch by a skin surface, presence orabsence of contact with an electrode, effects by stimulus such as anelectrostatic force, reproduction of cold or hot feeling using a heatabsorbing device or a heat emitting device, and the like. The hapticmodule 154 may be configured to transmit tactile effects (signals)through a user's direct contact, or a user's muscular sense using afinger or a hand. The haptic module 154 may be implemented in two ormore in number according to the configuration of the mobile terminal100.

The memory 160 may store a program for the processing and control of thecontroller 180. Alternatively, the memory 160 may temporarily storeinput/output data (e.g., phonebook data, messages, still images, videoand the like). Also, the memory 160 may store data relating to variouspatterns of vibrations and audio output upon the touch input on thetouch screen. The memory 160 may be implemented using any type ofsuitable storage medium including a flash memory type, a hard disk type,a multimedia card micro type, a memory card type (e.g., SD or DXmemory), Random Access Memory (RAM), Static Random Access Memory (SRAM),Read-Only Memory (ROM), Electrically Erasable Programmable Read-onlyMemory (EEPROM), Programmable Read-only Memory (PROM), magnetic memory,magnetic disk, optical disk, and the like. Also, the mobile terminal 100may operate a web storage which performs the storage function of thememory 160 on the Internet.

The interface unit 170 may generally be implemented to interface themobile terminal with external devices. The interface unit 170 may allowa data reception from an external device, a power delivery to eachcomponent in the mobile terminal 100, or a data transmission from themobile terminal 100 to an external device. The interface unit 170 mayinclude, for example, wired/wireless headset ports, external chargerports, wired/wireless data ports, memory card ports, ports for couplingdevices having an identification module, audio Input/Output (I/O) ports,video I/O ports, earphone ports, and the like.

The identification module may be configured as a chip for storingvarious information required to authenticate an authority to use themobile terminal 100, which may include a User Identity Module (UIM), aSubscriber Identity Module (SIM), a Universal Subscriber Identity Module(USIM), and the like. Also, the device having the identification module(hereinafter, referred to as ‘identification device’) may be implementedin a type of smart card. Hence, the identification device can be coupledto the mobile terminal 100 via a port.

Also, the interface unit 170 may serve as a path for power to besupplied from an external cradle to the mobile terminal 100 when themobile terminal 100 is connected to the external cradle or as a path fortransferring various command signals inputted from the cradle by a userto the mobile terminal 100. Such various command signals or powerinputted from the cradle may operate as signals for recognizing that themobile terminal 100 has accurately been mounted to the cradle.

The controller 180 typically controls the overall operations of themobile terminal 100. For example, the controller 180 performs thecontrol and processing associated with telephony calls, datacommunications, video calls, and the like. The controller 180 mayinclude a multimedia module 181 which provides multimedia playback. Themultimedia module 181 may be configured as part of the controller 180 oras a separate component. The controller 180 can perform a patternrecognition processing so as to recognize writing or drawing input onthe touch screen as text or image.

The power supply unit 190 serves to supply power to each component byreceiving external power or internal power under control of thecontroller 180.

Various embodiments described herein may be implemented in acomputer-readable medium using, for example, software, hardware, or somecombination thereof. For a hardware implementation, the embodimentsdescribed herein may be implemented within one or more of ApplicationSpecific Integrated Circuits (ASICs), Digital Signal Processors (DSPs),Digital Signal Processing Devices (DSPDs), Programmable Logic Devices(PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers,micro-controllers, microprocessors, other electronic units designed toperform the functions described herein, or a selective combinationthereof. In some cases, such embodiments are implemented by thecontroller 180. For software implementation, the embodiments such asprocedures and functions may be implemented together with separatesoftware modules each of which performs at least one of functions andoperations. The software codes can be implemented with a softwareapplication written in any suitable programming language. Also, thesoftware codes may be stored in the memory 160 and executed by thecontroller 180.

FIG. 2 is a front perspective view of a mobile terminal according to thepresent invention, and FIG. 3 is a rear perspective view of the mobileterminal of FIG. 2. Referring to FIGS. 2 and 3, the mobile terminal 200according to the present invention is a bar type mobile terminal.However, the present invention is not limited to this, but may beapplied to a slide type in which two or more bodies are coupled to eachother so as to perform a relative motion, a folder type, or a swingtype, a swivel type and the like. Further, the mobile terminal of thepresent invention may be also applicable to any portable electronicdevice having a camera and a flash, e.g., a portable phone, a smartphone, a notebook computer, a digital broadcasting terminal, PersonalDigital Assistants (PDAs), Portable Multimedia Players (PMPs), etc.

A case (casing, housing, cover, etc.) which forms the appearance of abody may include a front case 201, a rear case 202 covering an oppositesurface to the front case 201, and a cover 203 which constitutes therear surface of the mobile terminal 200 by being coupled to the rearcase 202. A space formed by the front case 201 and the rear case 202 mayaccommodate various components therein. Such cases may be formed byinjection-molded synthetic resin, or may be formed using a metallicmaterial such as stainless steel (STS) or titanium (Ti).

On the front surface of the body, may be disposed a display 210, a firstaudio output unit 211, a front camera 216, a side key 214, an interfaceunit 215 and a user input unit 217.

The display 210 includes a liquid crystal display (LCD) module, organiclight emitting diodes (OLED), e-paper, etc., each for visuallydisplaying information. The display 210 may include a touch sensingmeans for inputting information in a touch manner. Hereinafter, thedisplay 210 including the touch sensing means is called ‘touch screen’.Once part on the touch screen 210 is touched, content corresponding tothe touched position is input. The content input in a touch manner, maybe characters, or numbers, or menu items which can be set in each mode.The touch sensing means may be transmissive so that the display can beviewed, and may include a structure for enhancing visibility of thetouch screen at a bright place. Referring to FIG. 2, the touch screen210 occupies most of the front surface of the front case 201.

The first audio output unit 211 may be implemented as a receiver fortransmitting a call sound to a user's ear, or a loud speaker foroutputting each type of alarm sound or a playback sound of multimedia.

The front camera 216 processes image frames such as still images ormoving images, obtained by an image sensor in a video call mode or acapturing mode. The processed image frames may be displayed on thedisplay 210. The image frames processed by the front camera 216 may bestored in the memory 160, or may be transmitted to the outside throughthe wireless communication unit 110. The front camera 216 may beimplemented in two or more according to a user's interface.

The user input unit 217 is manipulated to receive a command forcontrolling the operation of the mobile terminal 200, and may include aplurality of input keys. The input keys may be referred to asmanipulation portions, and may include any type of ones that can bemanipulated in a user's tactile manner.

For instance, the user input unit 217 may be implemented as a domeswitch, or a touch screen, or a touch pad for inputting commands orinformation in a user's push or touch manner. Alternatively, the userinput unit 217 may be implemented, for example, as a wheel for rotatinga key, a jog, or a joystick. The user input unit 217 is configured toinput various commands such as START, END and SCROLL.

A side key 214, an interface unit 215, an audio input unit 213, etc. aredisposed on the side surface of the front case 201. The side key 214 maybe called ‘manipulation unit’, and may be configured to receive commandsfor controlling the operation of the mobile terminal 200. The side key214 may include any type of ones that can be manipulated in a user'stactile manner. Content input by the side key 214 may be variously set.For instance, through the side key 214, may be input commands such ascontrolling the front and rear cameras 216 and 221, controlling thelevel of sound output from the audio output unit 211, and converting acurrent mode of the display 210 into a touch recognition mode.

The audio output unit 213 may be implemented as a microphone forreceiving a user's voice, other sound, etc.

The interface unit 215 serves a path through which the mobile terminal200 performs data exchange, etc. with an external device. For example,the interface unit 215 may be at least one of a connection terminalthrough which the mobile terminal 200 is connected to an ear phone bycable or radio, a port for local area communication, e.g., an infrareddata association (IrDA) port, a Bluetooth portion, a wireless LAN port,and power supply terminals for supplying power to the mobile terminal200. The interface unit 215 may be a card socket for accommodating anexternal card such as a subscriber identification module (SIM) card, auser identity module (UIM) card or a memory card for storinginformation.

A power supply unit 240 and the rear camera 221 are disposed on the rearsurface of the body. A flash 222 and a mirror (not shown) may bedisposed close to the rear camera 221. When capturing an object by usingthe rear camera 221, the flash 222 provides light onto the object. Whenthe user captures an image of himself/herself by using the rear camera221, the mirror can be used for the user to look at himself/herselftherein.

The rear camera 221 may face a direction which is opposite to adirection faced by the front camera 216, and may have different pixelsfrom those of the front camera 216. For example, the front camera 216may operate with relatively lower pixels (lower resolution). Thus, thefront camera 216 may be useful when a user can capture his face and sendit to another party during a video call or the like. On the other hand,the rear camera 221 may operate with a relatively higher pixels (higherresolution) such that it can be useful for a user to obtain higherquality pictures for later use. The front camera 216 and the rear camera221 may be installed at the body so as to rotate or pop-up.

The power supply unit 240 is configured to supply power to the mobileterminal 200. The power supply unit 260 may be mounted in the body, ormay be detachably mounted to the body.

FIG. 4 is a perspective view illustrating a state in which a batterycase is removed in FIG. 3. FIG. 5 is a partial sectional view takenalong line IV-IV of FIG. 4. As shown in FIGS. 4 and 5, a vibration motor300 may be mounted in the mobile terminal so as to vibrate the mobileterminal. Conventionally, a rotary type motor was used as the vibrationmotor 300. However, the rotation of the rotary type motor is continuedfor a certain period of time after the power of the rotary type motor iscut off, and therefore, vibrations are maintained. Further, the rotarytype motor requires a certain space in which the rotary type motor canbe rotated, and therefore, it is difficult to miniaturize the mobileterminal. In addition, since kinetic energy is distributed in radialdirections of rotation about the rotation axis, it is difficult toconcentrate the kinetic energy in any one direction. Therefore, variousfactors such as prevention of secondary vibration are necessarilyconsidered in order to fix and support the vibration motor 300.Accordingly, in an exemplary embodiment, there is provided a linearvibration motor 300 formed so that a moving portion 320 can reciprocatein any one direction. Thus, linear vibration motor 300 can overcomedisadvantages of the conventional rotary type motor described above.

As shown in FIGS. 4 and 5, the vibration motor 300 according to theexemplary embodiment may be disposed near components sensitive tovibration, such as a speaker 231 or contact point 233. The speaker 231is formed so that a diaphragm in the speaker 231 is vibrated in thethickness direction thereof, and the contact point 233 is electricallyconnected in the thickness direction to another contact point of thebattery case. In this case, if vibrations are applied in the thicknessdirection to the speaker 231 and the contact point 233, the speaker 231and the contact point 233 may not show their original performances.Thus, if the vibration motor that does not vibrate in the longitudinaldirection but vibrates in the lateral direction is used in the exemplaryembodiment, the deployment of components in the mobile terminal can bemore freely performed. That is, the motor vibrating in the lateraldirection is used, so that it is possible to miniaturize the mobileterminal and to perform an optimal design on the deployment ofcomponents in the mobile terminal.

Although the vibration motor 300 according to the exemplary embodimentis used, the vibration motor 300 is preferably spaced apart from theimage input unit 221 at a predetermined interval. At least one buffermember 223 is provided between the image input unit 221 and thevibration motor 300, so that it is possible to prevent vibrationsapplied to the image input unit 221 during photographing.

FIG. 6 is a perspective view of a vibration motor shown in FIG. 3according to a first exemplary embodiment. FIG. 7 is an explodedperspective view of FIG. 6. FIG. 8 is a sectional view taken along lineV-V of FIG. 6. FIG. 9 is a sectional view taken along line VI-VI of FIG.6. Referring to FIGS. 6 to 9, the vibration motor 300 includes a housing310, a coil 360, a moving portion 320 and elastic members 351 and 352.

An internal space is formed in the housing 310 so that internalcomponents can be accommodated in the internal space. The housing 310may be formed in the shape of a rectangular parallelepiped having topand bottom surfaces and four side surfaces in the inner circumferencethereof. Alternatively, the housing 310 may be formed in the shape of aregular hexahedron. The housing 310 may be formed to include a firstcover 311 and a second cover 312.

It will be defined that the direction in which the length of therectangular parallelepiped is long is a length direction D1 and thedirection in which the length of the rectangular parallelepiped is shortis a width direction D2. In addition, it will be defined that the sidesurfaces opposite to each other in the length direction are first andthird sides S1 and S3, and the side surfaces opposite to each other aresecond and fourth sides S2 and S4.

Each corner portion of the housing 310 formed in the shape of therectangular parallelepiped may be formed to be a curved surface. Thus, acurved surface is formed at each end portion of the housing 310, so thatthe housing 310 can better support a load applied in the verticaldirection.

The coil 360 is formed in the housing 310, and may be formed on any oneof the first and second covers 311 and 312. The coil 360 is disposed onthe inner surface of the cover. The cover may have a mounting groove 313recessed from one surface thereof. In this case, the coil 360 isdisposed in the mounting groove 313. Thus, the thickness of the entiresecond cover 312 of the housing 310 can be decreased by the depth of themounting groove 313. The coil 360 may be disposed in plural numbers soas to further increase an electromagnetic force applied to the movingportion 320, when necessary.

The moving portion 320 may be formed to reciprocate between the firstand third sides S1 and S3 opposite to each other among the four sides ofthe housing 310. The moving portion 320 is formed to have apredetermined mass, and the mass at both ends in the length direction ofthe housing 310 may be formed greater than that of a central portion ofthe housing 310 so that displacement is increased in the direction wherethe moving portion 320 reciprocate.

The moving portion 320 includes a body 321, a magnet 322 and a yoke 323,and may be integrally formed with the magnet 322 and the yoke 323.Alternatively, the yoke 323 may be fixed to any one portion of thehousing 310, and the moving portion 320 may include only the magnet 322.The moving portion 320 has a groove recessed toward the inside thereof,and the magnet 322 may be mounted in the groove. The yoke 323 may bedisposed to cover the groove. Each of the magnet 322 and the yoke 323may be formed in the shape of a rectangular plate. Alternatively, themoving portion 320 may have a hole passing through the top and bottomsurfaces thereof, and the magnet 322 and the yoke 323 may be disposed tocover the hole.

The magnet 322 is formed at a central portion of the moving portion 320so as to generate a magnetic flux. The magnet 322 may be formed in asingle or plural numbers. In a case where the magnet 322 is formed inplural numbers, the magnets 322 may be disposed opposite to the yoke 323while being spaced apart from one another at a predetermined interval.

The magnet 322 and the coil 360 are disposed to generate anelectromagnetic force for allowing the moving portion 320 to reciprocatein the extending direction of the first and third sides S1 and S3.

The yoke 323 is disposed opposite to the magnet 322 so as to focus themagnetic flux of the magnet 322. In order to facilitate focusing themagnetic flux of the magnet 322, the yoke 323 may be formed to have asection broader than that of the magnet 322.

If external power is applied to the coil 360, the direction of currentflowing in the coil 360 is changed. In this case, the direction of thecurrent is changed, thereby reciprocating the moving portion 320. Here,AC power may be used as the external power, but DC power may be used asthe external power. In a case where the DC power is used as the externalpower, the moving portion 320 may be reciprocated using the supply andcutoff of the DC power and the elasticity and restoration of a spring.In this case, the coil 360 may be disposed to be biased to any one sidein the housing 310. That is, the coil 360 may be disposed to be biasedto any one side on the inner surface of the first or second cover 311 or312.

The elastic members 351 and 352 are disposed at both ends of the movingportion 320, respectively. More specifically, the elastic members 351and 352 may be disposed between the first side S1 of the housing 310 andthe moving portion 320 and between the third side S3 and the movingportion 320, respectively.

The elastic members 351 and 352 may be configured as coil springs,torsion springs, leaf springs, etc. In the exemplary embodiment, thecoil springs are used as the elastic members 351 and 352. As shown inthese figures, the elastic members 351 and 352 are disposed at both theends of the moving portion 320, respectively. Alternatively, the elasticmembers 351 and 352 may be formed in plural numbers between the firstside S1 and the moving portion 320 and between the third side S3 and themoving portion 320, respectively. The deployment of the elastic members351 and 352 can increase their elasticity and restoration with respectto the moving portion 320 and prevent the one-sided movement of themoving portion 320.

The elastic coefficients of the elastic members 351 and 352 may beformed different from each other. For example, the elastic coefficientof the elastic members 351 formed at the first side S1 is formed greaterthan that of the elastic members 352 formed at the third side S3, sothat the displacement of the moving portion 320 can be further increasedin the vibration of the vibration motor 300.

The housing 310 may have insertion grooves 315 into which the respectiveelastic members are inserted. The moving portion 320 may have insertiongrooves 325 into which the respective elastic members are inserted. Assuch, the elastic members are not fixed to the housing or the movingportion by welding or screws, and hence it is possible to decrease thepossibility that the elastic members may be disconnected or deformed.Thus, the durability of components can be improved.

As shown in FIG. 8, the moving portion 320 performing the reciprocatingmotion and the housing 310 are spaced apart from each other at a certaingap in the thickness direction thereof. The secondary vibration may begenerated in the thickness direction D3 (See FIG. 6) of the vibrationmotor 300 due to the gap. In order to prevent the secondary vibration,the moving portion 320 and the housing 310 are adhered closely to eachother, so that the vibration can be reduced due to the frictional forcebetween the moving portion 320 and the housing 310. Hereinafter, astructure for preventing the secondary vibration will be described withreference to the accompanying drawings.

As shown in FIGS. 6 and 7, roller members 340 are formed at both ends ofthe moving portion 320, facing the first and third sides S1 and S3 ofthe housing 310, respectively. The roller member 340 has a cylindricalbody 341 and shaft coupling portions 342 respectively protruded fromboth ends of the body 341. The cylindrical body 341 is formed to come inrolling contact with each of the first and second covers 311 and 312.The diameter of the cylindrical body 341 is formed greater than thethickness of the moving portion 320. Thus, when the moving portion 320reciprocates in the housing 310, the roller member 340 comes in rollingcontact with each of the top and bottom surfaces of the housing 310, andthe movement of the moving portion 320 in the housing 310 is guided bythe rolling member 340.

The shaft coupling portion 342 is coupled to the moving portion 320 soas to be relatively rotated with respect to the housing 310. The movingportion 320 has a groove into which each shaft coupling portion 342 canbe inserted.

The vibration motor 300 includes the roller members 340 as describedabove, so that it is possible to prevent the vibration of the movingportion 320 in the thickness direction in the internal space of thehousing 310.

Although not shown in these figures, each of the first and second covers311 and 312 may have a groove portion recessed from one surface thereof.The groove portion may be surface-treated in order to decrease thefrictional force between the housing 310 and the roller member 340. Asan example of the surface treatment, an oil layer may be formed on onesurface of the groove portion.

FIG. 10 is a sectional view of a vibration motor according to a secondexemplary view. FIG. 11 is a perspective view of a moving body shown inFIG. 10. As described above, a moving portion 420 and a housing 410 arespaced apart from each other at a certain gap. Therefore, the secondaryvibration may be generated in the thickness direction of the vibrationmotor 400 due to the gap. In order to prevent the secondary vibration inthe thickness direction, the moving portion 420 may include rollermembers 440. The roller members 440 may be formed on top and bottomsurfaces of the moving portion 420, facing inner surfaces of first andsecond covers 411 and 412, respectively.

The roller members 440 are formed in a ball shape to be inserted intothe moving portion 420. The moving portion 420 has grooves into whichthe respective roller members 440 are inserted, and each groove has anopened surface formed to have a diameter smaller than that of the rollermember 440. A spring may be disposed between the roller member 440 andthe moving portion 420 so as to elastically support the roller member440.

Only one side of the roller member 440 may come in rolling contact withthe housing 410, and the other side of the roller member 440 may bespaced apart from the inner surface of the groove of the moving portion420 at a predetermined interval. Alternatively, one side of the rollermember 440 may come in rolling contact with the housing 410, and theother side of the roller member 440 may come in rolling contact with thegroove of the moving portion 420.

The roller member 440 is preferably formed to have a small diameter sothat the frictional force between the roller member 440 and the housing410 is decreased by minimizing the portion of the roller member 440contacting the housing 410.

The vibration motor 400 includes the roller members 440 as describedabove, so that it is possible to prevent the vibration of the movingportion 420 in the thickness direction in an internal space of thehousing 410.

In the second exemplary embodiment, the other components (e.g., body421, magnet 422, yoke 423, springs 451 and 452 and coil 460) except theroller members 440 and the moving portion 420 coupled to the rollermembers 440 are identical or similar to those of the first exemplaryembodiment, and therefore, their detailed descriptions will be omittedand the reference numbers.

FIG. 12 is a sectional view of a vibration motor according to a thirdexemplary view. FIG. 13 is a perspective view of a second cover shown inFIG. 12. As described above, a moving portion 520 and a housing 510 arespaced apart from each other at a certain gap. Therefore, the secondaryvibration may be generated in the thickness direction of the vibrationmotor 500 due to the gap. In order to prevent the secondary vibration inthe thickness direction, the housing 510 may include roller members 514.The roller members 514 may be formed on inner surfaces of first andsecond covers 511 and 512, respectively.

The roller member 514 may be formed in plural numbers to be spaced apartfrom each other on each of the first and second covers 511 and 512. Theroller members 514 may be respectively disposed close to both side endsof the first and second covers 511 and 512 so as to support the movingportion 520 even at the maximum displacement in the reciprocating motionof the moving portion 520.

The roller member 514 has a cylindrical body and shaft coupling portionsrespectively protruded from both ends of the body. The shaft couplingportions of the roller member 514 are relatively rotatably coupled tothe housing 510. The shaft coupling portions are coupled to second andfourth sides of the housing 510, respectively. The second and fourthsides of the housing 510 have grooves into which the shaft couplingportions can be inserted, respectively.

One side of the roller member 514 may come in rolling contact with themoving portion 520, and the other side of the roller member 514 may comein rolling contact with the housing 510. Alternatively, only the oneside of the roller member 514 may come in rolling contact with themoving portion 520, and the other side of the roller member 514 may bespaced apart from the housing 510 at a predetermined interval.

The roller member 514 is preferably formed to have a diameter as smallas possible so that the frictional force between the roller member 514and the moving portion 520 is decreased by minimizing the portion of theroller member 514 contacting the moving portion 520.

The vibration motor 500 includes the roller members 514 as describedabove, so that it is possible to prevent the vibration of the movingportion 520 in the thickness direction in an internal space of thehousing 510.

In the second exemplary embodiment, the other components (e.g., body521, magnet 522, yoke 523, springs 551 and 552 and coil 560) except theroller members 514 and the housing 510 coupled to the roller members 514are identical or similar to those of the first exemplary embodiment, andtherefore, their detailed descriptions will be omitted.

As described in the first to third exemplary embodiments, the rollermembers are formed on the moving portion or the housing, so that it ispossible to guide the movement of the moving portion and to reduce orprevent vibrations in other directions except the moving direction.

Further, since the vibration in the thickness direction of the vibrationmotor can be minimized, it is possible to reduce the gap in thethickness direction, required in design so as to prevent abrasion due tothe contact between the moving portion and the housing. That is, it ispossible to reduce the gap in the thickness direction between the movingportion and the housing, thereby providing a slimmer vibration motor anda mobile terminal having the same.

FIG. 14 is a sectional view of a vibration motor according to a fourthexemplary view. FIG. 15 is an exploded perspective view of FIG. 14. FIG.16 is a sectional view taken along line VII-VII of FIG. 14. FIG. 17 is asectional view taken along line VIII-VIII of FIG. 14. FIG. 18 is asectional view taken along line IX-IX of FIG. 14. Referring to FIGS. 14to 18, the vibration motor 600 includes a housing 610, a coil 660, amoving portion 620 and elastic members 651 and 652. An internal space isformed in the housing 610 so that internal components can beaccommodated in the internal space. The housing 610 may be formed in theshape of a rectangular parallelepiped having top and bottom surfaces andfour side surfaces in the inner circumference thereof. Alternatively,the housing 610 may be formed in the shape of a regular hexahedron. Thehousing 610 may be formed to include a first cover 611 and a secondcover 612.

It will be defined that the direction in which the length of therectangular parallelepiped is long is a length direction D1 and thedirection in which the length of the rectangular parallelepiped is shortis a width direction D2. In addition, it will be defined that the sidesurfaces opposite to each other in the length direction are first andthird sides S1 and S3, and the side surfaces opposite to each other aresecond and fourth sides S2 and S4.

Each corner portion of the housing 610 formed in the shape of therectangular parallelepiped may be formed to be a curved surface. Thus, acurved surface is formed at each end portion of the housing 610, so thatthe housing 610 can better support a load applied in the verticaldirection.

The coil 660 is formed in the housing 610, and may be formed on any oneof the first and second covers 611 and 612. The coil 660 is disposed onthe inner surface of the cover. The cover may have a mounting groove 613recessed from one surface thereof. In this case, the coil 660 isdisposed in the mounting groove 613. Thus, the thickness of the entiresecond cover 612 of the housing 610 can be decreased by the depth of themounting groove 613. The coil 660 may be disposed in plural numbers soas to further increase an electromagnetic force applied to the movingportion 620, when necessary.

The moving portion 620 may be formed to reciprocate between the firstand third sides S1 and S3 opposite to each other among the four sides ofthe housing 610. The moving portion 620 is formed to have apredetermined mass, and the mass at both ends in the length direction ofthe housing 610 may be formed greater than that of a central portion ofthe housing 610 so that displacement is increased in the direction wherethe moving portion 620 reciprocate. The moving portion 620 includes abody 621, a magnet 622 and a yoke 623, and may be integrally formed withthe magnet 622 and the yoke 623. Alternatively, the yoke 623 may befixed to any one portion of the housing 610, and the moving portion 620may include only the magnet 622.

The moving portion 620 has a groove recessed toward the inside thereof,and the magnet 622 may be mounted in the groove. The yoke 623 may bedisposed to cover the groove. Each of the magnet 622 and the yoke 623may be formed in the shape of a rectangular plate. Alternatively, themoving portion 620 may have a hole passing through the top and bottomsurfaces thereof, and the magnet 622 and the yoke 623 may be disposed tocover the hole.

The magnet 622 is formed at a central portion of the moving portion 620so as to generate a magnetic flux. The magnet 622 may be formed in asingle or plural numbers. In a case where the magnet 622 is formed inplural numbers, the magnets 622 may be disposed opposite to the yoke 623while being spaced apart from one another at a predetermined interval.

The magnet 622 and the coil 660 are disposed to generate anelectromagnetic force for allowing the moving portion 320 to reciprocatein the extending direction of the first and third sides S1 and S3.

The yoke 623 is disposed opposite to the magnet 622 so as to focus themagnetic flux of the magnet 622. In order to facilitate focusing themagnetic flux of the magnet 622, the yoke 623 may be formed to have asection broader than that of the magnet 622.

If external power is applied to the coil 660, the direction of currentflowing in the coil 660 is changed. In this case, the direction of thecurrent is changed, thereby reciprocating the moving portion 620. Here,AC power may be used as the external power, but DC power may be used asthe external power. In a case where the DC power is used as the externalpower, the moving portion 620 may be reciprocated using the supply andcutoff of the DC power and the elasticity and restoration of a spring.In this case, the coil 660 may be disposed to be biased to any one sidein the housing 610. That is, the coil 660 may be disposed to be biasedto any one side on the inner surface of the first or second cover 611 or612.

The elastic members 651 and 652 are disposed at both ends of the movingportion 620, respectively. More specifically, the elastic members 651and 652 may be disposed between the first side S1 of the housing 310 andthe moving portion 620 and between the third side S3 and the movingportion 620, respectively. The elastic members 651 and 652 may beconfigured as coil springs, torsion springs, leaf springs, etc. In theexemplary embodiment, the coil springs are used as the elastic members651 and 652.

As shown in these figures, the elastic members 651 and 652 are disposedat both the ends of the moving portion 620, respectively. Alternatively,the elastic members 651 and 652 may be formed in plural numbers betweenthe first side S1 and the moving portion 620 and between the third sideS3 and the moving portion 620, respectively. The deployment of theelastic members 651 and 652 can increase their elasticity andrestoration with respect to the moving portion 620 and prevent theone-sided movement of the moving portion 620.

The elastic coefficients of the elastic members 651 and 652 may beformed different from each other. For example, the elastic coefficientof the elastic members 651 formed at the first side S1 is formed greaterthan that of the elastic members 652 formed at the third side S3, sothat the displacement of the moving portion 620 can be further increasedin the vibration of the vibration motor 600.

The housing 610 may have insertion grooves 615 into which the respectiveelastic members are inserted. The moving portion 620 may have insertiongrooves 625 into which the respective elastic members are inserted. Assuch, the elastic members are not fixed to the housing or the movingportion by welding or screws, and hence it is possible to decrease thepossibility that the elastic members may be disconnected or deformed.Thus, the durability of components can be improved.

As shown in FIG. 16, the moving portion 620 performing the reciprocatingmotion and the housing 610 are spaced apart from each other at a certaingap in the thickness direction thereof. The secondary vibration may begenerated in the thickness direction D3 (See FIG. 6) of the vibrationmotor 600 due to the gap. In order to prevent the secondary vibration,the moving portion 620 and the housing 610 are adhered closely to eachother, so that the vibration can be reduced due to the frictional forcebetween the moving portion 620 and the housing 610. Hereinafter, astructure for preventing the secondary vibration will be described withreference to the accompanying drawings.

As shown in FIGS. 17 and 18, guide portions 640 are formed at the secondand fourth sides S2 and S4 of the housing 610, respectively. The guideportions 640 are coupled to the housing 610 so as to guide the movingportion 620. The moving portion 620 has grooves 624 into which therespective guide portions 640 are inserted. Thus, in the vibration ofthe vibration motor 600, the moving portion 620 is formed to relativelyslide and move with respect to the housing 610. That is, the movingportion 620 having the grooves 624 can reciprocate while sliding alongthe guide portions 640. The guide portions 640 may be coupled to thesecond and fourth sides S2 and S4 of the housing 610, respectively. Tothis end, the housing 610 may have coupling portions 614.

In order to reduce the frictional force between the guide portion 640and the moving portion 620, the contact area between the guide portion640 and the moving portion 620 is preferably decreased. To this end, theguide portion 640 may have a guide groove 641 recessed from one surfacethereof.

Although not shown in these figures, the guide portion 640 may becoupled to a means such as a bearing for reducing the frictional force.

Although it has been illustrated in the exemplary embodiment that thegrooves are formed in the moving portion 620, and the guide portions 640are coupled to the housing 610, the grooves may be formed in the secondand fourth sides S2 and S4 of the housing 610, respectively, andprotruding members may be formed on the sides opposite to the second andfourth sides S2 and S4 so as to be protruded from the sides,respectively.

As described above, the grooves or guide portions are formed in themoving portion or the housing, so that it is possible to limit themoving direction of the moving portion and to reduce or preventvibrations in other directions except the moving direction.

Further, since the vibration in the thickness direction of the vibrationmotor can be minimized, it is possible to reduce the gap in thethickness direction, required in design so as to prevent abrasion due tothe contact between the moving portion and the housing. That is, it ispossible to reduce the gap in the thickness direction between the movingportion and the housing, thereby providing a slimmer vibration motor anda mobile terminal having the same.

The foregoing embodiments and advantages are merely exemplary and arenot to be construed as limiting the present disclosure. The presentteachings can be readily applied to other types of apparatuses. Thisdescription is intended to be illustrative, and not to limit the scopeof the claims. Many alternatives, modifications, and variations will beapparent to those skilled in the art. The features, structures, methods,and other characteristics of the exemplary embodiments described hereinmay be combined in various ways to obtain additional and/or alternativeexemplary embodiments.

As the present features may be embodied in several forms withoutdeparting from the characteristics thereof, it should also be understoodthat the above-described embodiments are not limited by any of thedetails of the foregoing description, unless otherwise specified, butrather should be construed broadly within its scope as defined in theappended claims, and therefore all changes and modifications that fallwithin the metes and bounds of the claims, or equivalents of such metesand bounds are therefore intended to be embraced by the appended claims.

The invention thus being described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

What is claimed is:
 1. A vibration motor comprising: a housing having atop surface, a bottom surface, and first to fourth side surfaces joiningthe top surface to the bottom surface, the first to fourth surfacesdefining an inner circumferential surface of the housing; a coilprovided in the housing; a moving portion provided in the housing, themoving portion being configured to reciprocate between the first andthird side surfaces arranged opposite to each other; an elastic memberprovided between the moving portion and the housing; and a roller memberprovided in the housing and arranged to come into rolling contact withthe top or bottom surface of the housing.
 2. The vibration motor ofclaim 1, wherein the roller member is coupled to the housing.
 3. Thevibration motor of claim 1, wherein the roller member is coupled to themoving portion.
 4. The vibration motor of claim 1, wherein the elasticmember is located between the moving portion and the first side surfaceor is located between the moving portion and the third side surface. 5.The vibration motor of claim 4, wherein the elastic member comprises: afirst elastic member located between the moving portion and the firstside surface; and a second elastic member located between the movingportion and the third side surface, and wherein an elastic coefficientof the first elastic member is different from an elastic coefficient ofthe second elastic member.
 6. The vibration motor of claim 5, whereinthe moving portion or the housing has insertion grooves into which theelastic members are inserted.
 7. The vibration motor of claim 1, whereinthe moving portion has a magnet and a yoke formed to determine thedirection of an electromagnetic force of the magnet.
 8. The vibrationmotor of claim 1, wherein the housing has first and second coverscoupled to each other, the first or second cover has a mounting grooverecessed from one surface thereof, and the coil is mounted in themounting groove.
 9. The vibration motor of claim 1, wherein areciprocating direction of the moving portion is arranged such that themoving portion moves closer to and further away from the first sidesurface while reciprocating.
 10. A mobile terminal, comprising: aterminal main body; and a vibration motor coupled to the terminal mainbody so as to vibrate the terminal main body, the vibration motorincluding: a housing having first and second covers coupled to eachother so as to define an internal space; a coil located in the housing;a moving portion configured to reciprocate in the internal space betweena first side of the housing and a third side of the housing opposite tothe first side, the moving portion reciprocating according to a changein electromagnetic field induced by the coil; and one of a roller memberprovided in the housing to come into rolling contact with the first orsecond cover of the housing; and guide portions provided at second andfourth sides of the housing so as to guide the moving portion, thesecond and fourth sides being adjacent to the first and third sides. 11.The mobile terminal of claim 10, wherein the roller member is coupled tothe housing.
 12. The mobile terminal of claim 10, wherein the rollermember is coupled to the moving portion.
 13. The mobile terminal ofclaim 10, wherein the elastic member is located between the movingportion and the first side or is located between the moving portion andthe third side.
 14. The mobile terminal of claim 13, wherein the elasticmember comprises: a first elastic member located between the movingportion and the first side; and a second elastic member located betweenthe moving portion and the third side, and wherein an elasticcoefficient of the first elastic member is different from an elasticcoefficient of the second elastic member.
 15. The mobile terminal ofclaim 14, wherein the moving portion or the housing has insertiongrooves into which the elastic members are inserted.
 16. The mobileterminal of claim 10, wherein the moving portion has a magnet and a yokeformed to determine the direction of an electromagnetic force of themagnet.
 17. The mobile terminal of claim 10, wherein the first or secondcover has a mounting groove recessed from one surface thereof and thecoil is mounted in the mounting groove.
 18. The mobile terminal of claim10, wherein a reciprocating direction of the moving portion is arrangedsuch that the moving portion moves closer to and further away from thefirst side while reciprocating.
 19. A mobile terminal, comprising: aterminal main body; and a vibration motor coupled to the terminal mainbody so as to vibrate the terminal main body, the vibration motorincluding: a housing having first and second covers coupled to eachother so as to define an internal space; a moving portion configured toreciprocate in the internal space between a first side of the housingand a third side of the housing opposite to the first side; an elasticmember located between the moving portion and the housing; and one of aroller member provided in the housing to come into rolling contact withthe first or second cover of the housing; and guide portions provided atsecond and fourth sides of the housing so as to guide the movingportion, the second and fourth sides being adjacent to the first andthird sides.
 20. The mobile terminal of claim 19, wherein the elasticmember is located between the moving portion and the first side or islocated between the moving portion and the third side.
 21. The mobileterminal of claim 20, wherein the elastic member comprises: a firstelastic member located between the moving portion and the first side;and a second elastic member located between the moving portion and thethird side, and wherein an elastic coefficient of the first elasticmember is different from an elastic coefficient of the second elasticmember.
 22. The mobile terminal of claim 21, wherein the moving portionor the housing has insertion grooves into which the elastic members areinserted.
 23. The mobile terminal of claim 19, wherein the movingportion includes a pair of grooves arranged opposite each other, eachgroove being configured to face a corresponding one of the second andfourth sides and to receive a corresponding guide portion therein. 24.The mobile terminal of claim 23, wherein each guide portion has a guidegroove recessed from one surface thereof so as to decrease a contactarea between the guide portion and the moving portion.
 25. The mobileterminal of claim 19, wherein the moving portion has a magnet and a yokefor to determine the direction of an electromagnetic force of themagnet.
 26. The mobile terminal of claim 19, wherein the first or secondcover has a mounting groove recessed from one surface thereof and a coilis mounted in the mounting groove.